Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka
The monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features h...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-07-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2021.645672/full |
| _version_ | 1819155084718637056 |
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| author | Danielle Su Danielle Su Danielle Su Sarath Wijeratne Sarath Wijeratne Charitha Bandula Pattiaratchi Charitha Bandula Pattiaratchi |
| author_facet | Danielle Su Danielle Su Danielle Su Sarath Wijeratne Sarath Wijeratne Charitha Bandula Pattiaratchi Charitha Bandula Pattiaratchi |
| author_sort | Danielle Su |
| collection | DOAJ |
| description | The monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features have implications for the development of the Island Mass Effect (IME) in the NIO. The IME in the NIO is characterized by areas of high chlorophyll concentrations identified through remote sensing to be located around the Maldives and Sri Lanka in the NIO. The IME around the Maldives was observed to reverse between the monsoons to downstream of the incoming monsoonal current whilst a recirculation feature known as the Sri Lanka Dome (SLD) developed off the east coast of Sri Lanka during the Southwest Monsoon (SWM). To understand the physical mechanisms underlying this monsoonal variability of the IME, a numerical model based on the Regional Ocean Modeling System (ROMS) was implemented and validated. The model was able to simulate the regional circulation and was used to investigate the three-dimensional structure of the IME around the Maldives and Sri Lanka in terms of its temperature and velocity. Results revealed that downwelling processes were prevalent along the Maldives for both monsoon periods but was applicable only to latitudes above 4°N since that was the extent of the monsoon current influence. For the Maldives, atolls located south of 4°N, were influenced by the equatorial currents. Around Sri Lanka, upwelling processes were responsible for the IME during the SWM but with strong downwelling during the NEM. In addition, there were also regional differences in intra-seasonal variability for these processes. Overall, the strength of the IME processes was closely tied to the monsoon current intensity and was found to reach its peak when the monsoon currents were at the maximum. |
| first_indexed | 2024-12-22T15:31:21Z |
| format | Article |
| id | doaj.art-23e6147b2b774962a4fb96287d33e049 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-22T15:31:21Z |
| publishDate | 2021-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-23e6147b2b774962a4fb96287d33e0492022-12-21T18:21:22ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452021-07-01810.3389/fmars.2021.645672645672Monsoon Influence on the Island Mass Effect Around the Maldives and Sri LankaDanielle Su0Danielle Su1Danielle Su2Sarath Wijeratne3Sarath Wijeratne4Charitha Bandula Pattiaratchi5Charitha Bandula Pattiaratchi6Oceans Graduate School, The University of Western Australia, Perth, WA, AustraliaThe UWA Oceans Institute, Indian Ocean Marine Research Centre, Perth, WA, AustraliaLOCEAN Laboratory, Sorbonne Université-CNRS-IPSL, Paris, FranceOceans Graduate School, The University of Western Australia, Perth, WA, AustraliaThe UWA Oceans Institute, Indian Ocean Marine Research Centre, Perth, WA, AustraliaOceans Graduate School, The University of Western Australia, Perth, WA, AustraliaThe UWA Oceans Institute, Indian Ocean Marine Research Centre, Perth, WA, AustraliaThe monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features have implications for the development of the Island Mass Effect (IME) in the NIO. The IME in the NIO is characterized by areas of high chlorophyll concentrations identified through remote sensing to be located around the Maldives and Sri Lanka in the NIO. The IME around the Maldives was observed to reverse between the monsoons to downstream of the incoming monsoonal current whilst a recirculation feature known as the Sri Lanka Dome (SLD) developed off the east coast of Sri Lanka during the Southwest Monsoon (SWM). To understand the physical mechanisms underlying this monsoonal variability of the IME, a numerical model based on the Regional Ocean Modeling System (ROMS) was implemented and validated. The model was able to simulate the regional circulation and was used to investigate the three-dimensional structure of the IME around the Maldives and Sri Lanka in terms of its temperature and velocity. Results revealed that downwelling processes were prevalent along the Maldives for both monsoon periods but was applicable only to latitudes above 4°N since that was the extent of the monsoon current influence. For the Maldives, atolls located south of 4°N, were influenced by the equatorial currents. Around Sri Lanka, upwelling processes were responsible for the IME during the SWM but with strong downwelling during the NEM. In addition, there were also regional differences in intra-seasonal variability for these processes. Overall, the strength of the IME processes was closely tied to the monsoon current intensity and was found to reach its peak when the monsoon currents were at the maximum.https://www.frontiersin.org/articles/10.3389/fmars.2021.645672/fullmonsoon currentsIndian OceanIsland Mass EffectRegional Ocean Model SystemSri Lanka and Maldives |
| spellingShingle | Danielle Su Danielle Su Danielle Su Sarath Wijeratne Sarath Wijeratne Charitha Bandula Pattiaratchi Charitha Bandula Pattiaratchi Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka Frontiers in Marine Science monsoon currents Indian Ocean Island Mass Effect Regional Ocean Model System Sri Lanka and Maldives |
| title | Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka |
| title_full | Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka |
| title_fullStr | Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka |
| title_full_unstemmed | Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka |
| title_short | Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka |
| title_sort | monsoon influence on the island mass effect around the maldives and sri lanka |
| topic | monsoon currents Indian Ocean Island Mass Effect Regional Ocean Model System Sri Lanka and Maldives |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2021.645672/full |
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